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sisting of almost identical notopodia and neuropodia each 
ramus bearing capillary and fureate sete; four dia- 
phragms at the posterior end of the first, second, third and 
fourth segments; heart median; a pair of slender, tubular 
nephridia in each segment, except in a few of the anterior 
ones. Burrowers, e.g., Scalibregma, Humenia. 
(5) Cotoraamipa.—Prostomium bears a pair ot 
grooved processes and several tentacles which act as gills 
and are usually greenish, due to the colour (chlorocruorin) 
of the contaimed blood; capillary setze in all segments 
except the peristomium; those of the anterior segments 
are directed forwards forming a protection for the head; 
limits of segments not clearly marked; only one or two 
internal septa present and a corresponding number of 
paws of nephridia. Burrowers in mud, e.g., Sephonostoma. 
(6) STERNASPID® containing the single genus Stern- 
aspis; body short, anterior region thickened and carrying 
on each side three rows of setze; on the ventral surface at 
the posterior end there is a bilobed horny plate, round the 
edges of which are some fifteen or sixteen tufts of long 
sete, and dorsal to these two bundles of filamentous gills; 
the ends of the genital ducts project freely. 
The family ArrnicoLtipa® contaims two’ genera 
Arenicola and Branchiomaldane. The latter is, however, 
only provisionally and doubtfully placed here, and as its 
anatomy and affinities are so uncertainly known it may be 
neglected in this account. The definition of the family 
may, therefore, be taken as that of the genus Arenicola, 
which may be summarised as follows : — 
Limnivorous Polycheta provided with numerous 
pais of branched gills not present on the anterior seven 
segments. Prostomium small or moderately well 
developed, bounded posteriorly by the nuchal organ, no 
tentacles or palps. Parapodia each consisting of a conical 
